Impact of invasive species on local ecosystems

Invasive species have defined themselves as a formidable army that poses a major threat to our  planet’s ecosystem. These species are non-native organisms belonging to other ecosystems and they  can be plants, animals or pathogens. Such species emerge from new environments and cause destructive  consequences in the host ecosystems. They are capable of influencing the local species, altering the environment, and  they may pose health risks to humans and result in economic losses to individuals, communities or nations. Therefore, gaining the knowledge of invasive species and their method of proliferation helps to combat them easily without any loss and also contributes to the conservation of ecosystems. 

Effect on local ecosystem 

Invasive species can cause the devastation of local ecosystems in several ways: 

1. Biodiversity loss: Invasive species compete more effectively for resources such as food, light and space with native species. Such competition results in the elimination or complete extinction of native species. For example, the arrival of brown tree snakes in Guan has eventually caused the loss of several bird species. 

2. Habitat loss: Some invasive species alter the abiotic factor of the ecosystem making it unsuitable for other endemic species. One of the best examples of such species is the freshwater invasive species known as Zebra mussel, which changes the physical properties of water. 

3. Predation and disease: Non-indigenous species are capable of eradicating the indigenous species that have not developed any means of defense to defend themselves against them. Furthermore, Invasive species bring new diseases against which native species possess no immunity. A good example is chytrid fungus (Batrachochytrium  dendrobatidis) that caused the disease chytridiomycosis, which caused a disastrous impact on amphibian populations. 

4. Economic impact: The economic loss due to invasive species is very high in current and future scenarios. Invasive species are capable of destroying crops, fisheries and forests. Combating them often requires expensive control mechanisms. For instance, the emerald ash borer alone caused the loss of billions of dollars of North American Ash tree.

How they spread 

Invasive species spread through various means, often helped by human activities: 

1. Global trade and travel: Various modes of transportation such as airplanes and ships unknowingly transport invasive species across borders. For example, the ballast water from the ship is one of the causes of introduction of invasive species in the ocean. 

2. Animals and horticulture: The trade of plants for farming or gardening and animals for pets is also behind the spread of invasive species. 

3. Climate change: The change in climatic conditions create a suitable environment for invasive species helping them to expand their territory. 

4. Human activities: Activities such as construction, deforestation and changes in land use  make the condition suitable for the invasive species to grow and thrive. 

Measures to manage or eliminate invasive species 

This involves a range of strategies, which includes early detection, prevention and long-term management. 

1. Prevention: One of the most effective preventive measures is to prevent the introduction of invasive species. The rules and regulations on importing plants and animals should be tightened and the public should be made aware of the dangers associated with the release of non-native species  

2. Early detection and rapid response: The species should be promptly identified, and  their progress should be stopped. Relevant programs should be introduced to monitor and report  on invasive species.  

3. Methods to manage species: a. Physical control: It involves manual removal like pulling out the invasive plant species or trapping the invasive animal, b. Chemical control: It involves the use of pesticides or herbicides, but it may have adverse effects on the environment, and c. Biological control: It involves the introduction of natural predators of the non-native species but it should be proceeded with caution as it may cause harm to native species also. 

4. Restoration: The best way to respond to the impact of the invasive species is by restoring  native habitat and supporting the native species.  

In conclusion, global biodiversity and ecosystem health are increasingly under threat from invasive  species. Given their widespread, and often severe consequences—in both time and space—they will  continue to require deliberate, sustained mitigation. By learning how they spread, and practicing both preventative and reactive measures, we can work to keep the natural balance of our  ecosystems to continue long into the future.

Saqib Shamim

Tri-Chandra Multiple Campus